1. Field of the Invention
The present invention relates to a current balance circuit and a power supply, and more particularly, to a current balance circuit having a protection function that protects a device by detecting an abnormal lamp operation after a predetermined time period in order to ensure a normal lamp operation, and further having a protection function that prevents the current balance circuit from being damaged during the preset time period by maintaining a constant level of power, being supplied to the lamp, and a power supply including the same.
2. Description of the Related Art
Recently, much attention has been drawn to liquid crystal display (LCD) devices that are smaller and lighter than existing display devices.
An LCD device necessarily employs a backlight unit that emits light. In addition, the LCD device may be provided with a power supply to supply power to lamps of the backlight unit.
The power supply may include a power supply circuit supplying power to lamps, and a current balance circuit maintaining the current balance of power being supplied to the lamps.
The current balance circuit may have a protection function that prevents device breakdown caused by an abnormal lamp operation such as an open lamp.
After a backlight unit having the above configuration is manufactured, commercial power is supplied to this backlight unit to check whether or not it is operating normally. To this end, the protection function of a current balance circuit is performed after a predetermined time period.
For a reduction in manufacturing costs, a current balance circuit, which had formerly been employed at each end of a lamp, is currently employed only at a single end of a lamp. Thus, the level of a voltage applied to the coil of the current balance circuit has been doubled compared to that of existing examples. For this reason, under the open-lamp condition, the coil may be burnt out due to the overvoltage applied to the coil.